And you can’t cheap out on the role. It’s also really hard to recognize the right kind of person for this without a somewhat Mature engineering team.

The wrong person in this type of role at a smaller company can things back significantly.

Yeah I saw that early in my career at a small company. Smart and charismatic guy in an architect role, impressed technical and non-technical people alike with his knowledge.

Now that I have more experience I realize he was more excited about cargo-culting big tech practices than about making sure our software was well-architected. We wasted so much time enthusiastically implementing his low-impact but technically exciting ideas.

The opposite can be a problem as well: a principal or architect who is stuck in their ways or not up to date on the platform will cause a lot of frustration and waste a lot of time. I've seen this unfortunately a few times: highly experienced and generally knowledgeable engineers who are disdainful of mobile platforms and don't feel they need to learn about the details and limitations of the system before pronouncing on technical designs (This especially applies to iOS for some reason IME).

Yeah, there's one principal DS at my company, and he's a net negative. I'm honestly amazed that they have hired him and kept him (which speaks to deeper issues with the company, unfortunately).

A bad principal/staff person has around the same level of impact as a bad manager/director, except it tends to cause more technical badness than social badness.